GB554076A - Improvements in or relating to photographic shutters - Google Patents

Abstract

554,076. Photographic shutters with lens diaphragms. KODAK, Ltd. Dec. 16, 1941, No. 16205. Convention date, June 17. [Class 98 (i)] To facilitate focusing at open aperture and subsequent closure of the diaphragm to the setting to be used for the exposure, a diaphragm carried by a photographic shutter is held in open position by a latch which is provided within the shutter and released through the operation of the shutter-setting lever when the release trigger is operated, whereupon the diaphragm is moved automatically towards the closed position until arrested by an adjustable stop at a predetermined position. As shown, the shutter is of the kind described in Specification 536,558, in which the setting-lever 8 is carried by an arcuate member 19 having a tooth 18 which, by depression of a button 16 can be engaged by a notched member 17, so arresting the movement when the shutter blades are fully open for focusing. When the diaphragm operating lever 22 is moved to the fully-open position it is retained by a spring- urged pivoted latch 25 which engages a lug 23 on it. When, after focusing, the lever 8 is moved to the position I to set the shutter, the end of the member 19 engages a pin 26 on the latch 25 and causes the latch to release the arm 22, which then moves under the action of a spring 31 to close the diaphragm until a lug 41 on the diaphragm ring engages a pre-adjusted stop to arrest the movement at the desired setting. The stop is adjusted by means of a pointer 14 and locked in position by compression of a spring 47 by means of a lock-nut 46.